Opiod Analgesia Flashcards Preview

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Flashcards in Opiod Analgesia Deck (18):
0

Name some opiates

Drugs derived from opium,
Morphine codeine papaverine

1

Define opiods

Opiod receptor agonist

2

Morphine

Derived from phenanthrene
Analgesic propetprties
Extensive first pass metabolism

3

Diamorphine

Heroin
Extensive first pass metabolism
More lipid soluble than morphine
Poor affinity for mu receptors

4

Codeine

Weak opiod for mu
50% morphines analgesia
Analgesic effects due to metabolism into morphine

5

Dihydrocodeine

Analgesic properties due to parent molecule or metabolite (dihydromorphine)

6

Tramadol

Atypical opiod
Analogue of codeine
Causes pyschosis due to serotonergic activity

7

Talpentadol

Mu receptor agonist

8

Oxycodone

Mu and kappa
Good bioavailability
Bad side effects

9

Hydromorphone

Ketone of morphine
More potent than mor
Highly water sol
Preferable in renal failure?

10

Methadone

Mu
Raecemic r= more affinity for r
S has additional nmda antagonistic effect and inhibits reuptake of 5ht and norepinephrine
Metabolised in liver, excreted in faeces therfore good for renal failure
Use for opiod addiction and neuropathic pain.

11

Fentanyl

Synthetic opiod agonist
V potent
Highly lipophilic
Metabolised in liver

12

Buprenorphine

Partial agonist, high affinity but low efficacy
Mu receptor
Use in opiod addiction

13

Naloxone

Opiod antagonist
Low oral availability
Rapid onset and short duration of action

14

Naltrexone

Orally active with long duration of action
Used in opiod addiction

15

Methylnaltrexone

Peripherally acting mu receptor antagonist
Used for opiod induced constijpation

16

Adverse effects of opiods

Respiratory depression
Nausea and vomiting
Sedation
Constipation
Hypotension

17

How do opiods work?

Directly bind to mu receptors in dorsal horn in spinal cord.
Opiods activate descending nerve fibres ffrom periaquiductal grey and raphe nuc, these control endogenous opiod containing interneurones, thereofre decreasing ascending pain pathways